Tidying up and adding tests still to be done.

PR for internal review purposes as prelude for PR to upstream
    PR'd against copy of upstream master.

Known issues to be fixed later:
- Styling is embedded in html file as prelude to re-styling
- No tests
- pep8 and pylint not looked at yet.

@jbau @jrbl @stvstnfrd @caesar2164 if you please.